Pseudo-AKI associated with targeted anti-cancer agents-the truth is in the eye of the filtration marker

Knowledge mapping and visualized analysis of research progress in onconephrology: a bibliometric analysis

OBJECTIVES

Onconephrology is an expanding subspecialty focused on the management of cancer patients with renal injury. This study used a comprehensive bibliometric analysis to emphasize the need for cooperation between oncologists and nephrologists, exploring current trends and future research areas in onconephrology.

METHODS

Relevant literature on onconephrology published between 1 January 2000 and 27 April 2024 was retrieved from the Science Citation Index Expanded of the Web of Science Core Collection, followed by manual screening. Bibliometric analyses were performed using CiteSpace, VOSviewer, and Bibliometrix software.

RESULTS

A total of 1,853 publications, including 1,647 articles and 206 reviews, by 11,606 authors from 2,757 institutions in 73 countries, were analyzed. Annual publications generally follow a steadily increasing trend, ranging from 25 to 161 documents. The United States (n = 464), The University of Texas MD Anderson Cancer Center (n = 39), Meletios A. Dimopoulos (n = 21), and Nephrology Dialysis Transplantation (n = 35) were the most productive country, institution, author, and journal, respectively. Immune checkpoint inhibitors, glomerular filtration rate, and cisplatin were clusters of highly cited references after 2015. Oxaliplatin, calcium, open-label, and thrombotic microangiopathy were trending topics after 2020. Outcome, acute kidney injury, immunotherapy, and chronic kidney disease were keyword bursts that persisted through 2024.

CONCLUSION

Current research of onconephrology is focusing on chemotherapeutic nephrotoxicity, kidney function assessment, dosing of chemotherapeutic agents in chronic kidney disease, glomerular disease in cancer, immunotherapy, and electrolyte disturbances. Future directions in this field include clinical trials and thrombotic microangiopathy.

Pseudo acute kidney injury in patients receiving CDK4/6 inhibitors

INTRODUCTION

CDK4/6 inhibitors (CDK4/6i) improve progression-free survival in patients with advanced oestrogen-receptor-positive breast cancer. However, all CDK4/6i may increase creatinine levels, which can indicate kidney injury. In vitro research has shown that CDK4/6i can also inhibit tubular secretion of creatinine, thereby causing the phenomenon 'pseudo-acute kidney injury (pseudo-AKI)'. The incidence of pseudo-AKI is, however, unknown. We aimed to determine this incidence by assessing cystatin C, a protein filtered in the glomerulus without being subject to tubular secretion, in patients with creatinine increase during CDK4/6i treatment.

METHODS

In this retrospective single-centre cohort study patients with breast cancer who received CDK4/6 inhibitors between January 1st 2017 and December 29th 2023 were screened for the incidence of creatinine increases suggesting potential kidney injury in the first six months of treatment. A significant creatinine increase was defined as 1) a creatinine plasma level of >90 µmol/L in women or >115 µmol/L in men and >10% increase from baseline creatinine plasma level or 2) a creatinine plasma level >1.5 times baseline creatinine or 3) an increase in creatinine plasma level from baseline with >26 µmol/L. Pseudo-AKI was diagnosed if the estimated glomerular filtration rate (eGFR) using cystatin C at the moment of creatinine increase was 1) equal or higher than eGFR using creatinine at baseline and/or 2) at least 25% higher than eGFR using creatinine at the moment of creatinine increase. The primary endpoint was the percentage of patients with pseudo-AKI analysed by means of the binomial probability test.

RESULTS

Of the 234 patients treated with a CDK4/6i, 41 (17.5%) had creatinine levels indicating an AKI. From 22 of these 41 patients, cystatin C could be determined in retrospectively available serum. Pseudo-AKI was found in 16 out of 22 patients (73%, 95% CI 50-89%). In 5 out of 41 patients (12%) the CDK4/6i dose was unjustly adjusted or the drug was stopped due to creatinine increase.

CONCLUSION

Pseudo-AKI has a high incidence in patients treated with CDK4/6i. Determining an eGFR based on the cystatin C value should therefore be considered as the first step when creatinine increases during CDK4/6i treatment.

Evaluation of cyclin-dependent kinase 4/6 inhibitor-induced serum creatinine elevations in patients with hormone receptor positive breast cancer

BACKGROUND

Cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) have improved the efficacy of endocrine therapy in hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer (BC) and are now used in both early-stage and metastatic disease. Recent case reports suggest that pseudo-serum creatinine (Scr) elevations are likely a class effect of CDK4/6i.

METHODS

This single-center retrospective analysis included patients aged ≥18 years who received at least one dose of palbociclib, ribociclib, or abemaciclib for the treatment of HR+/HER2- BC in the early or advanced setting. The primary objective was the incidence of pseudo-Scr elevation for each of the three agents. CDK4/6i-induced pseudo-Scr elevation was suspected when the Scr elevation could not be fully attributed to other causes. Secondary endpoints included the grade, onset, duration, and clinical consequences of pseudo-Scr elevation.

RESULTS

143 patients were included. Pseudo-Scr elevation was suspected in patients treated with palbociclib, ribociclib, or abemaciclib, with incidences of 16% (8/50), 14% (6/43), and 20% (10/50), respectively. Rates did not significantly differ between agents (p = 0.727). Among patients with CDK4/6i-induced pseudo-Scr elevation, all events were grade 1 (8.3%) or 2 (91.7%). The median onset from treatment initiation to first Scr elevation was 33.5, 42, and 21.5 days, for palbociclib, ribociclib, or abemaciclib, respectively.

CONCLUSION

Pseudo-Scr elevation appears to be a class effect of CDK4/6i, with similar rates of Scr elevation observed across the three agents currently FDA approved.

New perspectives of drug related kidney diseases and disorders

PURPOSE OF REVIEW

The aim of this review is to provide a discussion of new perspectives for up-to-date definitions, a contemporary classification system, and the potential role of stress and damage biomarkers in the context of drug related kidney diseases and disorders.

RECENT FINDINGS

Acute kidney disease (AKD) is a term recently introduced in the literature describing an abnormality in kidney structure and function that lasts for less than 3 months. Drugs in the context of AKD is described as a new perspective; referred to as drug induced AKD. A framework that includes drugs into the 2X2 classification schema for acute kidney injury (AKI) is provided. Finally, stress and damage biomarkers are examined to assess risk of drug associated AKI (D-AKI), differentiate which drugs cause AKI, differentiate drugs from other etiologies and assess the prognosis of D-AKI.

SUMMARY

Consistent definitions should be adopted with consideration to drug related diseases and disorders. Drug management can be guided using novel biomarkers to isolate a possible drug cause in the presence of more than one nephrotoxin or a nondrug cause, assisting with the diagnosis of pseudo-AKI, and deciding the likelihood AKI recovery. Furthermore, stress and damage kidney biomarkers provide the opportunity to detect subclinical AKI for early intervention in patients at high-risk for severe AKI.

Cancer therapy in patients with reduced kidney function

Chronic kidney disease (CKD) and cancer constitute two major public health burdens, and both are on the rise. Moreover, the number of patients affected simultaneously by both conditions is growing. The potential nephrotoxic effect of cancer therapies is particularly important for patients with CKD, as they are also affected by several comorbidities. Therefore, administering the right therapy at the right dose for patients with decreased kidney function can represent a daunting challenge. We review in detail the renal toxicities of anticancer therapies, i.e. conventional chemotherapy, targeted therapy, immune checkpoint inhibitors and radioligand therapies, issue recommendations for patient monitoring along with guidance on when to withdraw treatment and suggest dosage guidelines for select agents in advanced stage CKD. Various electrolytes disturbances can occur as the result of the administration of anticancer agents in the patient with decreased kidney function. These patients are prone to developing hyponatremia, hyperkalemia and other metabolic abnormalities because of a decreased glomerular filtration rate. Therefore, all electrolytes, minerals and acid base status should be checked at baseline and before each administration of chemotherapeutic agents. Moreover, studies on patients on kidney replacement therapy are very limited and only single cases or small case series have been published. Therefore, clinical therapeutical decisions in cancer patients with decreased function should be made by multidisciplinary teams constituted of medical oncologists, nephrologists and other specialists. Onconephrology is an evolving and expanding subspecialty. It is crucial to consider anticancer drug treatment in these patients and offer them a chance to be treated effectively.

Acute Kidney Injury Associated with Anticancer Therapies: Small Molecules and Targeted Therapies

Molecular targeted therapy has revolutionized cancer treatment by significantly improving patient survival compared with standard conventional chemotherapies. The use of these drugs targets specific molecules or targets, which block growth and spread of cancer cells. Many of these therapies have been approved for use with remarkable success in breast, blood, colorectal, lung, and ovarian cancers. The advantage over conventional chemotherapy is its ability to deliver drugs effectively with high specificity while being less toxic. Although known as "targeted," many of these agents lack specificity and selectivity, and they tend to inhibit multiple targets, including those in the kidneys. The side effects usually arise because of dysregulation of targets of the inhibited molecule in normal tissue. The off-target effects are caused by drug binding to unintended targets. The on-target effects are associated with inhibition toward the pathway reflecting inappropriate inhibition or activation of the intended drug target. Early detection and correct management of kidney toxicities is crucial to preserve kidney functions. The knowledge of these toxicities helps guide optimal and continued utilization of these potent therapies. This review summarizes the different types of molecular targeted therapies used in the treatment of cancer and the incidence, severity, and pattern of nephrotoxicity caused by them, with their plausible mechanism and proposed treatment recommendations.

Exploring and comparing renal adverse effects between PARP inhibitors based on a real-world analysis of post-marketing surveillance data

Objective

Poly (ADP-ribose) polymerase inhibitors (PARPis) are emerging targeted therapeutic agents in oncology, primarily indicated for ovarian and metastatic breast cancer. Acute kidney injury (AKI) has been observed in patients undergoing PARPi treatment, while there is still a lack of comprehensive comparisons of AKI associated with different PARPis. Our study aimed to extensively characterize the renal adverse effects (RAEs) of PARPi using real-world data.

Methods

Disproportionality analysis and Bayesian analysis were employed for data mining to identify suspected RAE cases after different PARPis use within the Food and Drug Administration's Adverse Event Reporting System from January 2004 to September 2023. The time to onset, fatality, and hospitalization rates of PARPi-related RAEs were also investigated.

Results

We identified 1,696 PARPi-related RAEs, predominantly affecting patients over 85 (56.31%). Veliparib exhibited a more pronounced association with RAEs compared to others, as indicated by the highest reporting odds ratio (ROR = 29.20, 95% CI = 8.79-96.97), proportional reporting ratio (PRR = 19.80, χ2 = 72.62), and empirical Bayes geometric mean (EBGM = 19.80, the lower 90% one-sided CI = 7.25). The median time to RAEs onset was 15 (interquartile range: 6-55.75) days following the initiation of PARPi therapy. PARPi-related RAEs generally led to a 28.15% hospitalization rate and a 4.34% fatality rate.

Conclusion

Although the majority present with reversible creatinine elevation, PARPi-related RAEs merits broader attention, given its potential for clinical consequences. We should strive to early identify those individuals who may have irreversible kidney damage. The focus should be directed toward monitoring renal function in individuals receiving PARPi, especially in senile people and those with a predisposition to AKI.

The impact of VEGF signalling pathway inhibitors and/or immune checkpoint inhibitors on kidney function over time: a single centre retrospective analysis

BACKGROUND

Drugs targeting angiogenesis and immunotherapy have transformed outcomes in renal cancer but may contribute to progressive kidney disease.

METHODS

We linked healthcare databases in the West of Scotland (spanning 2010-2020) to identify adults with renal cancer who received one or both classes of drugs. Over two years following initiation, estimated glomerular filtration rate (eGFR) slope was modelled using linear mixed-effects models. Additional renal outcomes used competing risk regression considering the competing risk of death.

RESULTS

Amongst 357 adults (62.5% male; median age 63.0 years, IQI 55.0-71.0), there was no significant change in eGFR (annual eGFR change +1.03 mL/min/1.73 m²/year, 95%CI -1.64 to +3.70), nor in subgroups of patients who had nephrectomy, metastatic cancer or an eGFR < 60 mL/min/1.73 m² prior to systemic therapy. A ≥ 40% decline in eGFR occurred in 82 people (23.0%) within one year of starting systemic therapy and was associated with pre-existing diabetes (subhazard ratio 1.89, 95%CI 1.05-3.41).

DISCUSSION

Anti-angiogenic and immune therapy had no substantial impact on the average change in eGFR but people with diabetes are at higher risk of clinically significant renal events. With appropriate monitoring, more widespread use of these agents in patients with renal impairment may be warranted.

Pharmacology of Tyrosine Kinase Inhibitors: Implications for Patients with Kidney Diseases

Tyrosine kinase inhibitors (TKI) have introduced a significant advancement in cancer management. These compounds are administered orally, and their absorption holds a pivotal role in determining their variable efficacy. They exhibit extensive distribution within the body, binding strongly to both plasma and tissue proteins. Often reliant on efflux and influx transporters, TKI undergo primary metabolism by intestinal and hepatic cytochrome P450 enzymes, with nonkidney clearance being predominant. Owing to their limited therapeutic window, many TKI display considerable intraindividual and interindividual variability. This review offers a comprehensive analysis of the clinical pharmacokinetics of TKI, detailing their interactions with drug transporters and metabolic enzymes, while discussing potential clinical implications. The prevalence of kidney conditions, such as AKI and CKD, among patients with cancer is explored in their effect on TKI pharmacokinetics. Finally, the potential nephrotoxicity associated with TKI is also examined.

Case report: A case of pseudo-acute kidney injury due to cyclin-dependent kinase inhibitor

Various classes of targeted therapies have emerged in the last few years, which have revolutionized cancer treatment, and improved the prognosis and survival of cancer patients. Unfortunately, these agents have serious toxic effects on the kidneys. Some of the toxic effects are hypertension, acute kidney injury (AKI), and proteinuria. One interesting phenomenon that has emerged recently is pseudo-acute kidney injury due to the interference with the tubular secretion of creatinine by some of the targeted therapeutic agents. Understanding this physiology is needed to avoid unnecessary investigation and withholding of lifesaving chemo regimen. Alternative methods to assess renal function such as cystatin C-based estimated glomerular filtration rate (eGFR) can differentiate true AKI from pseudo-AKI. Here, we describe one such case of pseudo-AKI from cyclin-dependent kinase (CDK) 4/6 inhibitor, abemaciclib, which inhibits tubular secretion of creatinine. Using cystatin-C-based eGFR revealed pseudo-AKI in this case.

Cancer drugs and acute kidney injury: new therapies and new challenges

PURPOSE OF REVIEW

Cancer therapies continue to evolve at a rapid pace and although novel treatments, including immunotherapies and targeted therapies have allowed for substantial improvements in cancer survival, they carry associated risks of acute kidney injury (AKI). We aim to summarize the existing literature on AKI associated with the spectrum of systemic cancer treatments, including conventional chemotherapies, newer immunotherapies, and the growing number of targeted cancer therapies, which may be associated with both AKI and 'pseudo-AKI'.

RECENT FINDINGS

Conventional cytotoxic chemotherapies (e.g. cisplatin and other platinum-based agents, methotrexate, pemetrexed, ifosfamide, etc.) with well recognized nephrotoxicities (predominantly tubulointerstitial injury) remain in widespread use. Immunotherapies (e.g., immune checkpoint inhibitors and CAR-T therapies) may be associated with kidney immune-related adverse events, most often acute interstitial nephritis, and rarely, glomerular disease. Recently, multiple targeted cancer therapies have been associated with reduced renal tubular secretion of creatinine, causing elevations in serum creatinine and apparent 'pseudo-AKI'. To complicate matters further, these agents have had biopsy-proven, 'true' kidney injury attributed to them in numerous case reports.

SUMMARY

Clinicians in nephrology and oncology must be aware of the various potential kidney risks with these agents and recognize those with clinically meaningful impact on both cancer and kidney outcomes.

Cystatin C should be routinely available for estimating kidney function

PURPOSE OF REVIEW

In this report, we summarize why the availability of cystatin C is important across a variety of clinical scenarios, the recent literature on when, why and in whom cystatin C testing should be considered, and how nephrologists can take practical steps to incorporate cystatin C testing into their practice.

RECENT FINDINGS

Large intra-individual discrepancies between estimated glomerular filtration rate by creatinine (eGFRcr) and estimated glomerular filtration rate by creatinine eGFRcys (known as eGFRdiff) are observed in at least 1 in 4 people. These differences are seen more commonly among more vulnerable individuals: older adults, females, non-White individuals and those living with multiple medical conditions. A large eGFRdiff, where eGFRcys is lower than eGFRcr, is associated with a plethora of adverse outcomes, including medication-associated adverse events, acute kidney injury, cardiovascular disease, kidney failure and all-cause mortality. Among studies that have measured GFR, eGFRcr-cys usually provides the most accurate estimation of kidney function compared to mGFR, including among participants with large discrepancies between eGFRcr and eGFRcys.

SUMMARY

Cystatin C improves sensitivity and specificity of chronic kidney disease diagnosis, improves detection of harmful acute and chronic changes in kidney function, improves precision of treatment eligibility and safety, and may reduce healthcare inequalities. Better education, curiosity, and motivation among nephrologists could substantially improve the availability and utilization of cystatin C.

[Pathology of the kidneys in malignant tumors of various localizations and antitumor therapy]

Non-tumorlesions of the kidneys in malignant neoplasms are very diverse. They can alter the results of chemotherapy and lead to death in the long term. In this regard, the related discipline of onconephrology has increasingly begun to be identified, which emphasizes the importance of diagnosing non-tumor kidney lesions in this category of patients. This review is devoted to the classification, diagnosis, course, prevention and treatment of non-tumor kidney lesions in patients with malignant neoplasms. There are four groups of lesions: mechanical damage; nephropathy due to anticancer therapy; paraneoplastic nephropathy; lesions associated with metabolic disorders. Kidney lesions in patients with malignant neoplasms are characterized by a variable course. In some cases, acute renal failure develops. Others are characterized by an asymptomatic course with an outcome in nephrosclerosis. Timely diagnosis and treatment of kidney lesions in malignant neoplasms can improve the quality of life and prognosis of patients with malignant neoplasms.